Refrigerator

ABSTRACT

To maintain an appropriate humidity in a refrigerator using a spray device to spray mist, without depending on a moisture sensor. A refrigerator ( 100 ) for forcibly circulating cold air which is gas cooled in a cooling compartment ( 110 ), the refrigerator including: a first storage compartment ( 107 ) disposed on the way of an air passage; a spray device ( 131 ) which sprays mist into the first storage compartment ( 107 ); a damper ( 145 ) disposed upstream of the first storage compartment ( 107 ); a delay unit ( 156 ) which generates, based on an open signal issued when the damper ( 145 ) is opened, a first signal for stopping the operation of the spray device ( 131 ) after an elapse of a first time period, and to generate, based on a close signal issued when the damper ( 145 ) is closed, a second signal for starting the operation of the spray device ( 131 ) after an elapse of a second time period; and a control unit ( 146 ) which controls the spray device ( 131 ).

TECHNICAL FIELD

The present invention relates to a refrigerator in which a spray deviceis installed to a storage space for vegetables and the like.

BACKGROUND ART

Influential factors for deterioration of freshness of vegetables includetemperature, humidity, ambient gas, microorganisms, and light. Becauserespiration and transpiration occur on the surfaces of vegetables, inorder to maintain the freshness of vegetables, it is necessary to reducerespiration and transpiration to a low level. Except for some vegetablessusceptible chilling damage, respiration of most vegetables is reducedat a low temperature, and transpiration can be prevented in highhumidity.

In recent years, household refrigerators are provided with a sealeddedicated container for the purpose of preserving vegetables, wherevegetables are cooled to an appropriate temperature, and the humidity inthe refrigerator is increased so as to keep transpiration fromvegetables under control. Here, there is known a spray device forspraying mist as a unit to increase the humidity in the refrigerator.

As a refrigerator provided with spraying capability of this type, thereis a refrigerator, in which a spray device humidifies the space in avegetable compartment so as to keep transpiration from vegetables undercontrol by spraying mist with an ultrasonic atomizing device when thevegetable compartment is at a low temperature (for example, see PatentLiterature 1).

FIG. 6 is a vertical sectional view of the conventional refrigeratordescribed in Patent Literature 1, and

FIG. 7 is a principal enlarged perspective view of an ultrasonicatomizing device provided in the vegetable compartment of theconventional refrigerator.

As shown in FIG. 6, a vegetable compartment 21 is provided in the lowerportion of a body case 26 of a refrigerator body 20, and the frontopening of the vegetable compartment 21 is designed to be closed by adrawer door 22, which may be drawn in a freely openable and closablemanner. The vegetable compartment 21 is partitioned from the upperrefrigerator compartment (not shown) by a partition plate 2. A fixinghanger 23 is fixed to the inner surface of the drawer door 22, and avegetable container 1 which stores food such as vegetables is mounted onthe fixing hanger 23. The top opening of the vegetable container 1 issealed by a lid 3. The inside of the vegetable container 1 is providedwith a thaw compartment 4, and the rear surface of the thaw compartment4 is provided with an ultrasonic atomizing device 5.

As shown in FIG. 7, the ultrasonic atomizing device 5 includes a mistdiffuser 6, a water storage container 7, a humidity sensor 8, and a hosereceiver 9. The water storage container 7 is connected to a defrostwater hose 10 via the hose receiver 9. A portion of the defrost waterhose 10 is provided with a cleaning filter 11 for cleaning defrostwater.

Hereinafter, the operation of the refrigerator as configured in thismanner is described.

First, cooling air cooled by a heat exchange cooler (not shown)circulates along the outer surface of the vegetable container 1 and alid 3 so that the vegetable container 1 is cooled, and thus the foodstored therein is cooled. The defrost water generated from the heatexchange cooler when the refrigerator is in operation is cleaned by thecleaning filter 11 as passing through the defrost water hose 10, and issupplied to the water storage container 7 of the ultrasonic atomizingdevice 5.

Next, when the humidity in the refrigerator is detected to be 90% orless by the humidity sensor 8, the ultrasonic atomizing device 5 startsto humidify the inside of the refrigerator and controls the humidity toan appropriate level in order to keep the vegetables in the vegetablecontainer 1 fresh. On the other hand, when the humidity in therefrigerator is detected to be 90% or more by the humidity sensor 8, theultrasonic atomizing device 5 stops excessive humidification.Consequently, the inside of the vegetable compartment 21 is kept in themost appropriate humidity state by the ultrasonic atomizing device 5.

CITATION LIST Patent Literature

-   [PTL 1]-   Japanese Unexamined Patent Application Publication No. 6-257933

SUMMARY OF INVENTION Technical Problem

However, in the above-described conventional configuration, start andstop of the atomizing device is generally controlled based on therefrigerator's humidity detected by the humidity sensor. With thismechanism, precision or responsiveness of the detection may cause aproblem. In this case, because the humidity in the refrigerator cannotbe obtained accurately, there is a problem in that a degree of forcedhumidification could be too much or too less. Particularly, in a storagecompartment of the refrigerator, i.e., substantially sealed, lowtemperature space, an excessive amount of atomization causes water rotof vegetables and the like, and condensation forms in the refrigerator.On the other hand, a smaller amount of atomization causes aninsufficient humidification of the storage compartment, and thusvegetables and the like cannot be kept fresh.

The present invention solves the above-described existing problems, andit is an object of the invention to provide a refrigerator capable ofmaintaining the humidity more appropriately and efficiently withoutdepending on a humidity sensor, provided that the refrigerator isequipped with an atomizing unit to increase freshness keeping ability byspraying mist.

Solution to Problem

In order to solve the above-described existing problem, a refrigeratoraccording to one aspect of the present invention provides a refrigeratorfor circulating cold air which is a gas cooled in a cooling compartment,the refrigerator including: a storage compartment partitioned with heatinsulation; a spray device configured to supply mist to the storagecompartment; a damper provided in an air passage for circulating thecold air from the cooling compartment to the storage compartment; acontrol unit configured to control the spray device so that an operationof the damper and an operation of the spray device are coordinated; anda delay unit configured to command the control unit to stop theoperation of the spray device after an elapse of a first time periodsince the damper is opened.

In addition, one aspect of the present invention provides a refrigeratorfor circulating cold air which is a gas cooled in a cooling compartment,the refrigerator including: a storage compartment partitioned with heatinsulation; a spray device configured to supply mist to the storagecompartment; a damper provided in an air passage for circulating thecold air from the cooling compartment to the storage compartment; acontrol unit configured to control the spray device so that an operationof the damper and an operation of the spray device are coordinated; anda delay unit configured to command the control unit to start theoperation of the spray device after an elapse of a second time periodsince the damper is closed.

This configuration allows an atomizing unit to efficiently spray mistand to appropriately humidify the inside of the storage compartment.

Advantageous Effects of Invention

The refrigerator of the present invention not only achieves appropriateand efficient atomization to improve the quality of itself provided withan atomization device, but also the amount of power required to controlthe atomizing device can be reduced to a minimum.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a vertical sectional view of a refrigerator in Embodiment 1 ofthe present invention.

FIG. 2 is a principal front view of a vegetable compartment and theperipheral area of the refrigerator in Embodiment 1 of the presentinvention.

FIG. 3 is a sectional view taken along line A-A of FIG. 2 of therefrigerator in Embodiment 1 of the present invention.

FIG. 4 is a functional block diagram of the refrigerator in Embodiment 1of the present invention.

FIG. 5 is an operation timing chart of the refrigerator in Embodiment 1of the present invention.

FIG. 6 is a vertical sectional view of a vegetable compartment of aconventional refrigerator.

FIG. 7 is a principal enlarged perspective view of an ultrasonicatomizing device provided in the vegetable compartment of theconventional refrigerator.

DESCRIPTION OF EMBODIMENTS

A first aspect of the invention provides a refrigerator according to oneaspect of the present invention provides a refrigerator for circulatingcold air which is a gas cooled in a cooling compartment, therefrigerator including: a storage compartment partitioned with heatinsulation; a spray device configured to supply mist to the storagecompartment; a damper provided in an air passage for circulating thecold air from the cooling compartment to the storage compartment; acontrol unit configured to control the spray device so that an operationof the damper and an operation of the spray device are coordinated; anda delay unit configured to command the control unit to stop theoperation of the spray device after an elapse of a first time periodsince the damper is opened.

A second aspect of the invention provides a refrigerator for circulatingcold air which is a gas cooled in a cooling compartment, therefrigerator including: a storage compartment partitioned with heatinsulation; a spray device configured to supply mist to the storagecompartment; a damper provided in an air passage for circulating thecold air from the cooling compartment to the storage compartment; acontrol unit configured to control the spray device so that an operationof the damper and an operation of the spray device are coordinated; anda delay unit configured to command the control unit to start theoperation of the spray device after an elapse of a second time periodsince the damper is closed.

The atomizing unit is controlled according to the timing of opening andclosing of the damper when the flow of cold air is changed, the flow airflow governing occurrences of condensation and drying in the peripheryof the atomizing unit. Therefore, an atomizing operation can beperformed in the most suitable state for atomization, and thus anatomizing device which has an efficient mist spraying function and anexcellent energy-saving feature can be mounted on a refrigerator.

A third aspect of the invention further includes a condensationprevention heater configured to dry a periphery of the spray device byheating, wherein the control unit is configured to cause thecondensation prevention heater to operate for a predetermined dryingperiod until the close signal is received when the damper is in a closedstate and the spray device is in operation based on the close signal andthe second signal.

Accordingly, unnecessary energization of the condensation preventionheater is not performed when the periphery of the atomizing unit isalready dry because of subsequent atomizing operation, and thus, notonly power consumption can be reduced, but also an increase of thetemperature in the storage compartment can be reduced.

According to a fourth aspect of the invention, the spray deviceincludes: a thin rod-shaped atomizing electrode; a counter electrodewhich is disposed so as to oppose and be spatially apart from theatomizing electrode; and a voltage applying unit configured to apply avoltage across the atomizing electrode and the counter electrode withthe atomizing electrode at a negative potential and the counterelectrode at a reference potential.

The voltage to be applied can be reduced to a lower level, and thusminiaturization of the atomizing device can be achieved.

Hereinafter, an embodiment of the present invention is described withreference to the drawings. The invention is not limited by theembodiment.

Embodiment 1

FIG. 1 is a vertical sectional view of a refrigerator in Embodiment 1 ofthe present invention; FIG. 2 is a principal front view of a vegetablecompartment and the peripheral area of the refrigerator in Embodiment 1of the present invention; FIG. 3 is a sectional view taken along lineA-A of FIG. 2 of the refrigerator in Embodiment 1 of the presentinvention; FIG. 4 is a functional block diagram of the refrigerator inEmbodiment 1 of the present invention; and FIG. 5 is an operation timingchart of the refrigerator in Embodiment 1 of the present invention.

In FIGS. 1 to 4, a heat-insulating main body 101 of a refrigerator 100includes an outer body 102 principally made of steel sheet, an innerbody 103 molded with a resin such as ABS, and foam, e.g., foamed heatinsulation material such as hard urethane foam, for filling the spacebetween the outer body 102 and the inner body 103. Thus, theheat-insulating main body 101 is thermally insulated from the peripheryand is partitioned into a plurality of storage compartments.

A configuration is made such that a refrigerator compartment 104 as asecond storage compartment is disposed at the top portion of theheat-insulating main body 101; a changing compartment 105 as a fourthstorage compartment, and an icemaker compartment 106 as a fifth storagecompartment are disposed side-by-side below the refrigerator compartment104; a vegetable compartment 107 as a first storage compartment isdisposed below the switchable compartment 105 and the icemakercompartment 106; and a freezer compartment 108 as a third storagecompartment is disposed at the lowest portion.

The refrigerator compartment 104 is normally set at a temperature of 1to 5° C. whose lower limit does not cause freezing because ofrefrigeration preservation. The vegetable compartment 107 is set at atemperature of 2 to 7° C. which is equivalent to or slightly higher thanthe temperature of the refrigerator compartment 104. The freezercompartment 108 is set at a temperature in a freezing temperature range,i.e., normally in a range of −22 to −15° C. for preservation byfreezing. However in order to improve freezing preservation quality, thefreezer compartment 108 may be set at a low temperature of −30 to −25°C., for example.

The switchable compartment 105 can switch the temperature range to apredetermined temperature range between the refrigeration temperaturerange and the freezing temperature range, in addition to therefrigeration temperature range of 1 to 5° C., the temperature range forvegetables of 2 to 7° C., and the freezing temperature range of −22 to−15° C. The switchable compartment 105 is a storage compartment havingan independent door, and is installed by the side of the icemakercompartment 106, and the independent door is often a drawer-type door.

In the present embodiment, the switchable compartment 105 coversswitchable temperature ranges including the refrigeration temperaturerange and the freezing temperature range. However, the switchablecompartment 105 may be a storage compartment for specific use ofswitching to the above-mentioned temperature range between therefrigeration temperature range and the freezing temperature range,under the condition that refrigeration is performed in the refrigeratorcompartment 104 and the vegetable compartment 107, and freezing isperformed in the freezer compartment 108. Alternatively, the switchablecompartment 105 may be a storage compartment whose temperature range isfixed to specific temperature range.

The icemaker compartment 106 makes ice by an automatic ice machine (notshown) provided at the upper portion of the icemaker compartment 106,using the water sent from the water storage tank (not shown) in therefrigerator compartment 104, and stores the ice in an ice storagecontainer (not shown) disposed at the lower portion of the icemakercompartment 106.

The top of the heat-insulating main body 101 has a step-like recess inthe direction to the back of the refrigerator 100. A machine chamber 101a is formed in the step-like recess which stores a compressor 109, andthe components in the high voltage side of refrigeration cycle, such asa dryer (not shown) for removing water content. That is to say, themachine chamber 101 a which stores the compressor 109 is formed byembedding in the rear area of the uppermost portion of the refrigeratorcompartment 104.

The matters related to the essence of the invention describedhereinafter in the present embodiment may be applied to a typical,conventional refrigerator, in which a machine chamber is provided in therear area of a storage compartment at the lowest portion of theheat-insulating main body 101, and the compressor 109 is disposed in themachine chamber. Alternatively, the refrigerator 100 may have what iscalled a mid-freezer configuration, in which the installment positionsof the freezer compartment 108 and the vegetable compartment 107 arereplaced.

Next, the back side of the vegetable compartment 107 and the freezercompartment 108 is provided with a cooling chamber 110 which generatescold air. A back side partition wall 111 is formed between the vegetablecompartment 107 and the cooling chamber 110, and/or between the freezercompartment 108 and the cooling chamber 110. The back side partitionwall 111 forms a carrier air passage for flowing cold air to eachcompartment, and further has heat insulating property in to thermallyinsulate each compartment from the cold air.

A cooler 112 is disposed in the cooling chamber 110, and a cooling fan113 is disposed in the upper space of the cooler 112. The cooling fan113 has a function of forcibly circulating the cold air which is cooledby the cooler 112. Specifically, the cooling fan 113 is a fan that sendsthe cold air cooled by the cooler 112 to the refrigerator compartment104, the switchable compartment 105, the icemaker compartment 106, thevegetable compartment 107, and the freezer compartment 108. A heater 114is disposed in the lower space of the cooler 112. In the case of thepresent embodiment, the heater 114 is a radiant heater which is made ofglass tube, and defrosts the frost and ice adhering to the cooler 112and its periphery. A drain pan 115 for receiving defrosted waterproduced at the time of defrosting is disposed at the lower portion ofthe heater 114. A drain tube 116 is connected from the backmost portionof the drain pan 115 to the outside of the refrigerator 100. Anevaporation pan 117 is disposed outside the refrigerator 100 downstreamof the drain tube 116.

In the vegetable compartment 107, there are disposed a lower storagecontainer 119 which is placed on a frame attached to the drawer door 118of the vegetable compartment 107, and an upper storage container 120which is placed on the lower storage container 119. In the vegetablecompartment 107, a lid 122 for substantially sealing the upper storagecontainer 120 is disposed with the drawer door 118 closed. In the caseof the present embodiment, the lid 122 is supported by a first partition123 and the inner body 103 which are provided above the vegetablecompartment 107. The lid 122 is in close contact with the right and leftsides and the back side of the upper surface of the upper storagecontainer 120. In addition, the lid 122 is in substantially contact withthe front side of the upper surface of the upper storage container 120.Furthermore, the boundary space between the right and left lower sidesof the back surface of the upper storage container 120 and the lowerstorage container 119 is reduced in a range so that the moisture in thefood storage does not escape, the range keeping the upper and lowercontainers from contact with each other when the upper storage container120 is in use.

The space between the lid 122 and the first partition 123 serves as anair passage for passing cold air. The air passage allows cold air toflow, the cold air being discharged from an outlet port 124 for thevegetable compartment 107, the outlet port 124 being formed in the backside partition wall 111. There is also a space provided between thelower storage container 119 and a second partition 125 below the lowerstorage container 119, and the space serves as an air passage forpassing cold air. The lower portion of the back side partition wall 111disposed on the rear surface side of the vegetable compartment 107 isprovided with an inlet port 126 for the vegetable compartment 107, theinlet port 126 serving as a port for cold air to return to the cooler112, the cold air having cooled the inside of the vegetable compartment107 and having undergone heat exchange.

The matters related to the essence of the invention describedhereinafter in the present embodiment may be applied to a typical,conventional refrigerator whose door is opened or closed by a frameattached to the door and a rail provided in the inner body.

The back side partition wall 111 is a member which thermally insulatesthe air passage, the cooling chamber 110 from the vegetable compartment107. In the case of the present embodiment, the back side partition wall111 forms the back wall of the vegetable compartment 107, and includes aheat insulation portion 152 having insulation property, and a surfaceportion 151 disposed on the surface of the heat insulation portion 152.The surface portion 151 is composed of resin such as ABS which isrelatively hard and allows surface design treatment. The heat insulationportion 152 is composed of low thermally conductive resin with lowdensity such as styrofoam in order to secure the insulation property.

An electrostatic spray device 131 is embedded in the back side partitionwall 111, the electrostatic spray device 131 having an atomizing unit139 which electrostatically atomizes water content. Specifically, arecess portion is provided on the back side partition wall 111 betweenthe vegetable compartment 107 and the cooling chamber 110, and the spraydevice 131 is installed in the recess. By providing the recess portionin the back side partition wall 111, the space in the recess portion haslow insulation property, and thus the temperature in the recess portionbecomes lower than that in other portions in the vegetable compartment107.

The thickness of part of the heat insulation portion 152 where a coolingpin 134 of the back side partition wall 111 is disposed is 10 mm orless. Accordingly, especially the cooling pin 134 is cooled, and thetemperature thereof becomes lower than that in the vegetable compartment107.

A condensation prevention heater 155 is embedded in the back sidepartition wall 111. The condensation prevention heater 155 is located ina neighborhood of the recess, i.e., where the spray device 131 isembedded, and between the surface portion 151 and the heat insulationportion 152.

A cover 153 is provided in front of the cooler 112, and in the back ofthe vegetable compartment 107, a discharge air passage 141 of thefreezer compartment 108 is provided between the cover 153 and the backside partition wall 111.

In the air passage formed in the back of the heat insulation portion152, there is provided a damper 145 for adjusting a circulation amountof the cold air which cools each storage compartment.

The spray device 131 includes an atomizing unit 139, a voltage applyingunit 133, and a case 137. The case 137 is provided with an atomizingport 132 and a supply port 138 for supplying water content such asmoisture to the case 137. The atomizing unit 139 includes a counterelectrode 136 and an atomizing electrode 135. The atomizing electrode135 is attached to the cooling pin 134. The cooling pin 134 is composedof high thermally conductive member such as aluminum or stainless steel.The atomizing electrode 135 and the cooling pin 134 are disposed so asto secure high thermal conduction therebetween.

The cooling pin 134 is fixed to the case 137 in such a manner that aportion of the cooling pin 134 projects outwardly from the case 137. Thecounter electrode 136 is an electrode in a doughnut disk shape (ringshape) on the vegetable compartment 107 side with respect to thelocation of the counter electrode 136 that faces the atomizing electrode135. The counter electrode 136 is attached to the case 137 so as to bespaced apart from the atomizing electrode 135 by a certain distance. Thecentral axis of the hole in the counter electrode 136 is aligned withthe central axis of the atomizing port 132, and the tip end of theatomizing electrode 135 is disposed on the central axis. In the presentembodiment, the counter electrode 136 is in a flat doughnut disk shape,but may be in a dome shape with an opening in the center so that the endof the atomizing electrode 135, and the surface of the counter electrode136 that faces the end of the atomizing electrode 135 are spaced apartby the same distance. By adopting the above-mentioned shape to thecounter electrode 136, efficiency of spraying mist can be improved.

In addition, the spray device 131 includes the voltage applying unit 133for applying a voltage on a connection between the counter electrode 136and the atomizing electrode 135. In the case of the present embodiment,the voltage applying unit 133 is disposed in a neighborhood of theatomizing unit 139. The voltage applying unit 133 has two electrodes forapplying a voltage, the negative potential side of which is electricallyconnected to atomizing electrode 135, while the positive potential sideof which is electrically connected to the counter electrode 136. Forexample, a negative high potential lower than a reference potential, ina range of −10 to −4 kV is applied to the atomizing electrode 135, whilethe counter electrode 136 is connected to a reference potential GND, andthus a high voltage is applied to the counter electrode 136.

The voltage applying unit 133 is configured to acquire a signal S1 froma delay unit 156 in a control unit 146 of the refrigerator 100, and tobe able to set the high voltage ON/OFF. The operation of theelectrostatic spray device 131 is controlled by ON/OFF of the voltageapplying unit 133.

The control unit 146 acquires a signal S2 from an inside temperaturedetection unit 150, and a signal S3 from the damper 145 to controlstart/stop of the spray device 131, the signal S2 for detecting atemperature inside the refrigerator compartment 104 which is the secondstorage compartment of the refrigerator 100, and the signal S3 foradjusting an amount of cooling and an air flow. The control unit 146also controls start/stop of the condensation prevention heater 155 fordrying the atomizing electrode 135. A signal S4 is used for the control.

Hereinafter, the operation and effect of the refrigerator as configuredin this manner is described.

First, the operation of a refrigeration cycle is described. Therefrigeration cycle starts to operate and a cooling operation isperformed based on a signal from a control substrate (not shown)according to a temperature setting in the refrigerator. The hightemperature, high pressure coolant discharged by the operation of thecompressor 109 is condensed and liquefied to a certain degree by acondenser (not shown), and is further condensed and liquefied whileflowing through a refrigerant piping (not shown) disposed in the lateralsurfaces or the rear surface of the refrigerator 100, or the frontfrontage of the refrigerator 100, and preventing condensation of therefrigerator 100, and finally reaches a capillary tube (not shown).Subsequently, in the capillary tube, the coolant is decompressed whileexchanging heat with a suction pipe (not shown) to the compressor 109,and becomes low temperature, low pressure liquid coolant, and reachesthe cooler 112.

The low temperature, low pressure liquid coolant exchanges heat with theair in each storage compartment such as the air in the discharge airpassage 141 of the freezer compartment 108, the air being transported bythe operation of the cooling fan 113, and thus the coolant in the cooler112 is vaporized. At this point, cold air for cooling each storagecompartment in the cooling chamber 110 is generated.

The low temperature cold air generated in the cooling chamber 110 issent to the refrigerator compartment 104, the switchable compartment105, the icemaker compartment 106, the vegetable compartment 107, andthe freezer compartment 108 by cooling fan 113.

The cold air is shunted using the structure of the air passage and thedamper 145, and is sent to each compartment so as to maintain thedesired temperature range of the compartment.

The amount of cooling air for the refrigerator compartment 104 isadjusted by the damper 145 based on a temperature sensor (not shown)provided in the refrigerator compartment 104, and thus the refrigeratorcompartment 104 is cooled to a desired temperature. Particularly, thevegetable compartment 107 is adjusted at a temperature of 2 to 7° C. byan ON/OFF operation of distribution of the cold air and/or a heatingunit (not shown).

In the vegetable compartment 107, there are disposed an outlet port 124for the vegetable compartment 107, which discharges cold air, and aninlet port 126 which sucks the cold air in the vegetable compartment107. The outlet port 124 is a port for discharging the cold air whichhas cooled the refrigerator compartment 104, and is disposed on the wayof a return air passage to refrigerator compartment 140 for returningcold air to the cooler 112. The inlet port 126 is a port for sucking thecold air which has been discharged to the vegetable compartment 107, andhas flown along the outer periphery of the upper storage container 120and the lower storage container 119, and has cooled the inside of theupper storage container 120 and the lower storage container 119 in anindirect manner. The cold air sucked through the inlet port 126 for thevegetable compartment 107 is returned to the cooler 112.

The air passage and the cooling chamber 110 exist behind the back sidepartition wall 111 that is opposite side to the side where the spraydevice 131 is attached, and the cooling pin 134 of the spray device 131which is nearest to the air passage and the cooling chamber 110 isstrongly cooled by the cold air which is just generated in the cooler112 by the operation of the cooling system. Specifically, the cold airwhich has been cooled by the cooler 112 and has reached a neighborhoodof the cooling fan 113 has a temperature of approximately 25 to −15° C.The cold air passing through the air passage cools the cooling pin 134at a temperature of approximately −10 to 0° C. by heat conduction at athin portion of the heat insulation portion 152. At this time, becausethe cooling pin 134 is high thermally conductive member, the cooling pin134 tends to transfer low heat, and also because the cooling pin 134 andthe atomizing electrode 135 are connected to each other in a highlyconductive state, the atomizing electrode 135 is also cooled at atemperature of approximately −10 to 0° C.

The vegetable compartment 107 is cooled so that the temperature thereofis maintained at a range of 2 to 7° C. And the vegetable compartment 107is in a relatively high humidity condition because of the transpirationfrom vegetables and the like. Consequently, the atomizing electrode 135which is cooled via the cooling pin 134 has a temperature below the dewpoint temperature, and thus water is generated and adheres to theatomizing electrode 135 including the tip end thereof which is the tipend for spraying.

The voltage applying unit 133 applies a high voltage across theatomizing electrode 135 and the counter electrode 136 (for example, theatomizing electrode 135 at −10 to −4 kV, the counter electrode 136 atGND), the atomizing electrode 135 to which water drops adhering beingthe negative voltage side, and the counter electrode 136 being thepositive voltage side, and thus the operation of the spray device 131starts.

At this point, a corona discharge occurs between the atomizing electrode135 and the counter electrode 136, and the water drops (in the presentembodiment, the water drops are what water content in the air condenses)adhering to the tip end for spraying of the atomizing electrode 135 ischarged and made into minute particles by electrostatic energy. Further,because the water drops are electrically charged, the water drops becomeinvisible microscopic mist with a minute electrical charge in the orderof several nm because of Rayleigh fission. The microscopic mist containsozone, OH radicals, oxygen radicals that are assumed to be generated bythe above-mentioned corona discharge.

Although the difference in voltages applied to the electrodes is anextremely high voltage of 4 to 10 kV, the discharge current value atthis moment is on the order of several μA, and the input is an extremelylow value of 0.5 to 1.5W, and thus proper spraying is performed.

In this manner, the microscopic mist on the order of nano meter which isgenerated in the atomizing electrode 135 is sprayed outwardly from theatomizing unit 139. At this moment, an ion wind is generated and the airin the case 137 flows out from the atomizing unit 139. In this moment,the inside of the case 137 has negative pressure, and thus additionalhighly humid air flows into the atomizing unit 139 through the supplyport which is provided on the side of the case 137. By repeating thiscycle, the spray device 131 can spray mist continuously.

Furthermore, the generated microscopic mist reaches the inside of thelower storage container 119 with the ion wind. Because the mist containsextremely small particles, the mist easily diffuses, and thus themicroscopic mist also reaches the upper storage container 120. Thesprayed mist is generated by a high pressure discharge, and thus has anegative electrical charge.

In the vegetable compartment 107, especially green vegetable leaves,fruits, and the like out of vegetables and fruits are preserved, andthese vegetables and fruits tend to wither because of theirtranspiration or transpiration while they are preserved. The vegetablesand fruits which are preserved in the vegetable compartment 107 normallyinclude those vegetables and fruits that have withered somewhat becauseof transpiration on the way home after their purchase or transpirationwhile they are preserved, and thus has a positive electrical charge.Thus, negatively charged mist tend to gather on the surfaces ofvegetables, and accordingly freshness of the vegetables is enhanced.

In addition, the microscopic mist on the order of nano meter which hasbeen sprayed from the spray device 131 and has adhered to the surfacesof the vegetables has ozone in addition to a negative electrical chargedue to a great number of OH radicals contained in the mist.Consequently, the mist sprayed from the spray device 131 hasantibacterial properties, disinfection properties, and the like, andthus freshness of the vegetables preserved in the storage compartmentmay be further improved. Additionally, by the negatively charged mistadhering to the surfaces of vegetables, toxic substances such asagricultural chemicals adhering to the surfaces of vegetables can comeoff or can be captured by the mist, and thus can be easily removed.Furthermore, an effect of removing agricultural chemicals due tooxidative decomposition can be achieved. In addition, by applying astimulus of the mist to the vegetables, the antioxidant action occurs,and an effect of an increase of nutrients such as the amount of vitaminC is promoted.

The refrigerator compartment 104 is controlled to be in a desiredtemperature range by the damper 145 as described above. That is to say,when the refrigerator compartment 104 has a temperature higher than thedesired temperature, the refrigerator compartment 104 is cooled byopening the damper 145 to introduce colder air. When the damper 145 isopened, relatively dry air which has cooled the refrigerator compartment104 flows into the vegetable compartment 107 through the outlet port124, and thus the vegetable compartment 107 is cooled. Thus, in therefrigerator 100 in the present embodiment, cold air does not directlyflow into the vegetable compartment 107, and the damper 145 does notcontrol the cold air, either. That is to say, the vegetable compartment107 is disposed on the way of the return air passage to refrigeratorcompartment 140, along which the cold air which flows out from therefrigerator compartment 104 returns to the cooling chamber 110.

In the case where the environment in the vegetable compartment 107 has ahigh humidity, it can be considered that the atomizing electrode 135 hasexcessively condensed water. In this case, by utilizing the return airfrom the relatively dry refrigerator compartment 104 controlled by thedamper 145, the excessively condensed water drops on the atomizingelectrode 135 are dried, and an appropriate amount of condensed water isformed, and thus the atomizing electrode 135 is controlled to be in anatomization feasible state.

In general, compared with the cold air in the refrigerator compartment104, the cold air in the vegetable compartment 107 has high humidity,and the cold air which flows in from the refrigerator compartment 104 isrelatively dry air in the vegetable compartment 107, and thus the coldair which flows in from the refrigerator compartment 104 is used fordrying the atomizing electrode 135 in the present embodiment.

That is to say, the air flow, the ambient temperature, and the dry statein the vegetable compartment 107 vary in accordance with the opening andclosing of the damper 145 of the refrigerator compartment 104 locatedupstream of the vegetable compartment 107 in the air passage of coldair. Accordingly, it can be assumed that the opening and closing of thedamper 145 which is provided upstream of the vegetable compartment 107in the air passage causes the cold air flow to change, the cold air flowgoverning condensation and drying in the periphery of the atomizing unit139 among the environmental changes typical to the storage compartmentof the refrigerator 100. Thus, the opening and closing of the damper 145are essential factors which have an influence on the periphery of theatomizing unit 139, i.e., condensation and drying in the atomizingelectrode 135.

However, drying by the cold air at the time of opening of the damper 145may not be able to sufficiently dry the excessively condensed watercontent of the atomizing electrode 135, and thus the condensationprevention heater 155 is energized regularly, and the atomizingelectrode 135 is forcibly dried regularly. Accordingly, impracticabilityof atomization due to excessive condensation of the atomizing electrode135 can be prevented.

Thus, the open and close operations of the damper 145 of therefrigerator compartment 104 located upstream of the vegetablecompartment 107 is an essential timing which makes it possible topredict that the environment in the periphery of the vegetablecompartment 107 and the atomizing unit 139 changes, particularly, thecold air flow in the periphery of the atomizing unit 139 changes.However, the opening and closing timing of the damper 145 does notimmediately cause the humidity in a periphery of the atomizing unit 139in the vegetable compartment 107 to change, and the humidity changeswith a time lag. Consequently, ON/OFF of the high voltage is controlledby the voltage applying unit 133 with a prescribed time interval ofdelay from the open/close signal of the damper 145, the delay being madeby the delay unit 156, and thus mist is sprayed efficiently in ahumidity range of an atomization feasible region.

In the present embodiment, a configuration has been described, in whichthe spray device 131 is attached to the back side partition wall 111,however, as long as the cooling pin 134 can be cooled, the spray device131 may be attached to the first partition wall 123 so that mist can besprayed from the top surface of the vegetable compartment 107. In thiscase, the spray device 131 can be easily installed in a structural senseby changing the shape of the cooling pin 134 from a rod-like shape to aplate-like shape, and slimming down the spray device 131.

Next, the content of control on the specific spray device 131 isdescribed using the operation timing chart of FIG. 5.

First, in the operational state of the refrigerator 100 at the timing ofpoint A of FIG. 5, the inside temperature detection unit 150 detects thetemperature in the refrigerator compartment 104 which is the secondstorage compartment, and inputs a result of the detection to the controlunit 146, the result of the detection being a signal S2. At this point,the control unit 146 has acquires a “closed state” signal from thedamper 145, and determines that the inside temperature is not high basedon the signal S2, and maintains the damper 145 in a closed state. Thatis to say, the refrigerator compartment 104 is not to cooled. Becausethe damper 145 is closed, dry cold air does not flow into the vegetablecompartment 107, and thus the inside of the vegetable compartment 107has a high humidity. The humidity in the periphery of the atomizing unit139 is also in the atomization feasible region (shaded area (hatchingarea) in FIG. 5) in which the spray device 131 can atomize. Thus, thevoltage applying unit 133 sets the high voltage ON, and sets the spraydevice 131 in an operation state so that the spray device 131 spraysmicroscopic mist from the atomizing electrode 135 into the vegetablecompartment 107. During the time of spray, the condensation preventionheater 155 is in a stopped state, and is considered to be a normalcondensation/atomization period of the atomizing electrode 135.

Next, at the timing of point B, the control unit 146 determines that thetemperature in the refrigerator compartment 104 has become high, basedon signal S2, and generates an open signal, and sets the damper 145 inan open state, and maintains the state. Accordingly, cold air flows intothe refrigerator compartment 104 to cool the refrigerator compartment104, while the open state signal (included in the signal S3) from thedamper 145 is inputted to the control unit 146, and the open signal isinputted to the delay unit 156.

Thus, because the damper 145 is open, the dry cold air flows into thevegetable compartment 107, and thus the humidity in the vegetablecompartment 107 starts to decrease. However, the humidity in a peripheryof the atomizing unit 139 does not immediately decrease, and theoperation of the spray device 131 continues for the prescribed timebecause the current humidity is in the atomization feasible region.

At the timing of point C after the prescribed time elapses, the damper145 is in an open state, and thus the humidity in the vegetablecompartment 107 and in a periphery of the atomizing unit 139 furtherdecreases, and deviates from the atomization feasible region. At thistiming, the delay unit 156 starts to count elapsed time from the moment(point B) when an open signal of the damper 145 is generated, andoutputs a first signal (included in the signal S1) for controlling theoperation of the spray device 131 when a predetermined first time periodT1 elapses. When the spray device 131 acquires the first signal, thehigh voltage is set to OFF by the voltage applying unit 133, and thespray device 131 stops the operation. By previously defining theprescribed time for the first time period T1 between the time (point B)when the state of the damper 145 is changed from “close” to “open”, andthe time (point C) when the spray device 131 is stopped, atomizationcontrol can be performed without using a complicated humiditymeasurement method. For the value of T1 in this case, 10 to 15 minutesis preferable, but T1 may be experimentally prescribed freely inaccordance with the cooling performance of the actually usedrefrigerator 100.

Next, at the timing of point D, the control unit 146 determines that thetemperature in the refrigerator compartment 104 has become low, based ona result of the detection by the inside temperature detection unit 150,and generates a close signal, and sets the damper 145 in an closedstate, and maintains the state. Accordingly, the refrigeratorcompartment 104 is not cooled, while the closed state signal (includedin the signal S3) from the damper 145 is inputted to the control unit146, and the close signal is inputted to the delay unit 156.

Thus, because the damper 145 is closed, no dry cold air flows into thevegetable compartment 107, and thus the humidity in the vegetablecompartment 107 starts to increase. However, the humidity in a peripheryof the atomizing unit 139 does not immediately increase, and theoperation of the spray device 131 remains stopping for the prescribedtime because the current humidity is out of the atomization feasibleregion.

Next, at the timing of point E after the prescribed time elapses, thedamper 145 is in a closed state, and thus the humidity in the vegetablecompartment 107 and in a periphery of the atomizing unit 139 furtherincreases, and enters the atomization feasible region. Thus, at thistiming, the delay unit 156 starts to count elapsed time from the momentwhen the close signal is generated, and outputs a second signal(included in the signal S1) for controlling the operation of the spraydevice 131 when a predetermined second time period T2 elapses. When thespray device 131 acquires the second signal, the high voltage is set toON by the voltage applying unit 133, and the spray device 131 is set inoperation. By previously defining the prescribed time for the secondtime period T2 between the time (point D) when the state of the damper145 is changed from “open” to “close”, and the time (point E) when thespray device 131 is started, atomization control can be performedwithout using a complicated humidity measurement method in a similarmanner as in the case of the first time period T2. For the value of T2in this case, 5 to 10 minutes is preferable, but T2 may beexperimentally prescribed freely in accordance with the coolingperformance of the actually used refrigerator 100.

Then in the condensation/atomization period between the timing of pointF and the timing of point G, the above-described operation between pointB and point E is repeated for two cycles, and efficient spraying of mistis continued.

Next, at the timing of point H, when the damper 145 is in a closed stateand the spray device 131 is in operation, the humidity in a periphery ofthe atomizing unit 139 is also in an atomization feasible region, theatmosphere and the like of a periphery of the atomizing unit 139 iswarmed by operating the condensation prevention heater 155. A dryingtime period T3 during which the condensation prevention heater 155 isoperated is set between the current time and the timing of point I whenthe damper 145 is in an open state next time. Accordingly, even when theatomizing electrode 135 is in an excessive condensation state, theatomizing electrode 135 can be thoroughly dried, and thus mist can besmoothly sprayed subsequently. For the value of T3 in this case,approximately 10 minutes is preferable, but T3 may be experimentallyprescribed freely in accordance with the thermally conductiveperformance of the actually used refrigerator 100. In this manner, thedrying time period of the atomizing electrode 135 is periodicallyprovided.

The delay unit 156 desirably set that the first period (T1)>=the secondperiod (T2). This is because, in a storage compartment with highhumidity like the vegetable compartment 107, the rate of decrease in thehumidity after the damper 145 is opened is greater than the rate ofincrease in the humidity after the damper 145 is closed. In other words,the rate of humidity decrease in the first period is slow, and thus evenwhen a longer first time period is set, spraying in a high humiditystate can be performed, while the rate of humidity increase in thesecond period is fast, and thus even when a shorter second time periodis set, spraying in a high humidity state can be performed.

In this manner, by setting the first time period to be equal to orlonger than the second time period, spraying in a high humidity statecan be performed, and thus the spray rate of the spray device 131 can beimproved, which performs spraying to the peripheral air by usingcondensed water.

Furthermore, in the present embodiment, when mist is sprayed into astorage compartment of the refrigerator, the spray rate of mist of thespray device 131 is preferably 50% or more and 80% or less. This isbecause, in a low-temperature high humidity state like the state of arefrigerator, when a large quantity of mist is sprayed, mist on the wallsurface is condensed, and thus a small quantity of mist is preferablysprayed for a long time. Therefore, in order to achieve a sufficienteffect continuously with a small quantity of mist, the spray rate of 50%or more is required.

In the present embodiment, in order to stably supply a small quantity ofmist, a drying time period of the atomizing electrode 135 isperiodically provided. By setting the spray rate of 80% or less foroperation states including a state in which the spray device is inoperation, but spraying is not performed because of dry state, excessivecondensation of the atomizing electrode 135 is suppressed, and thusreliable and stable spraying of mist can be achieved.

In the present embodiment, during a drying time period T3, even at thetime of switching between condensation and dry time periods, the spraydevice 131 is set in operation in order to efficiently spray mist,however, the spray device 131 may be stopped to improve energy savingperformance.

In the present embodiment, it has been described that the timing ofenergizing the condensation prevention heater 155 is once for everythree cycles of the open and close operations of the damper 145.However, as long as the atomizing electrode 135 is thoroughly dried, thetiming of the energization may be once for an arbitrary number ofcycles.

As described above, the refrigerator in the present embodiment includes:the vegetable compartment 107 which is a thermally insulated storagecompartment; the atomizing unit 139 for spraying mist into the vegetablecompartment 107; the damper 145 disposed upstream of the vegetablecompartment 107 in the air passage; the condensation prevention heater155 for drying a periphery of the atomizing unit 139; and the controlunit 146 for controlling the operation of the atomizing unit 139 usingthe open/close signals of the damper 145 as an input. By the controlunit 146 having the delay unit 156 which controls the atomizing unit 139by delaying an atomizing operation by a prescribed time with respect tothe open/close signals of the damper 145, mist spraying operation isperformed in an appropriate humidity state of the atomizing unit 139,which is in the atomization feasible region. Thus efficient, andappropriate atomization can be achieved, and fresh quality of vegetablesmay be further improved.

In this case, when the state of the damper 145 is changed from “open” to“closed”, the spray device 131 is set in operation after a prescribedtime elapses, while when the state of the damper 145 is changed from“closed” to “open”, the spray device 131 is stopped after a prescribedtime elapses.

As described above, in the present embodiment, for the open/closesignals of the damper 145, i.e. for both of the opening signal and theclosed signal, by delaying an atomizing operation by a prescribed time,the spray device 131 can be operated more efficiently in the actualoperation of the refrigerator 100, efficient mist spraying can beachieved.

In this manner, appropriate atomization is achieved efficiently, and notonly the quality of the refrigerator 100 provided with the spray device131 is improved, but also the amount of power required to control thespray device 131 can be reduced to a low level.

When the timing of energizing the condensation prevention heater 155 isonce for a plurality of cycles of the open and close operations of thedamper 145, the number of times of energizing the condensationprevention heater 155 is reduced, and thus not only the powerconsumption can be further reduced, but also an increase of thetemperature in the vegetable compartment 107 is suppressed, therebyallowing high quality food preservation.

The atomizer head 139 includes an electrostatic atomization systemhaving the atomizing electrode 135 and the counter electrode 136, theatomizing electrode 135 being connected to a negative potential lowerthan a reference potential, and the counter electrode 136 beingconnected to the reference potential GND. By applying a high voltage bythe voltage applying unit 133, microscopic mist on the order of nanometer, having negatively charged OH radicals is sprayed more efficientlythan in the case where the atomizing electrode 135 is connected to thepositive side rather than the reference potential GND. Therefore, aninput power to the voltage applying unit 133 can be small, and thusminiaturization of the spray device 131 can be achieved, and mistspraying can be performed in less space.

In the present embodiment, the storage compartment for spraying mist inthe refrigerator 100 is the vegetable compartment 107, but may be astorage compartment in other temperature range such as the refrigeratorcompartment 104 or the switchable compartment 105. In this case, variousapplications can be developed.

In the present embodiment, heat conduction from the air passage throughwhich cold air flows is utilized for a cooling unit for cooling eachstorage compartment formed of the cooler 112, however, a cool unit usinga Peltier element may also be considered.

INDUSTRIAL APPLICABILITY

As described above, the refrigerator according to one aspect of thepresent invention can achieve appropriate atomization in a storagecompartment, and thus can be applied to not only a household orindustrial refrigerator, or a refrigerator exclusively for vegetables,but also low-temperature distribution of food such as vegetables, orwarehouse.

REFERENCE SIGNS LIST

100 Refrigerator

101 Heat-insulating main body

102 Outer case

107 Vegetable compartment (storage compartment)

109 Compressor

111 Back side partition wall

112 Cooler

113 Cooling fan

124 Outlet port for vegetable compartment

131 Electrostatic spray device

132 Atomizing port

133 Voltage applying unit

134 Cooling pin

135 Atomizing electrode

136 Counter electrode

139 Atomizing unit

145 Damper

155 Condensation prevention heater

156 Delay unit

1. A refrigerator for circulating cold air which is a gas cooled in acooling compartment, said refrigerator comprising: a storage compartmentpartitioned with heat insulation; a spray device configured to supplymist to said storage compartment; a damper provided in an air passagefor circulating the cold air from the cooling compartment to saidstorage compartment; a control unit configured to control said spraydevice so that an operation of said damper and an operation of saidspray device are coordinated; and a delay unit configured to commandsaid control unit to stop the operation of said spray device after anelapse of a first time period since said damper is opened.
 2. Arefrigerator for circulating cold air which is a gas cooled in a coolingcompartment, said refrigerator comprising: a storage compartmentpartitioned with heat insulation; a spray device configured to supplymist to said storage compartment; a damper provided in an air passagefor circulating the cold air from the cooling compartment to saidstorage compartment; a control unit configured to control said spraydevice so that an operation of said damper and an operation of saidspray device are coordinated; and a delay unit configured to commandsaid control unit to start the operation of said spray device after anelapse of a second time period since said damper is closed.
 3. Therefrigerator according to claim 1, wherein said delay unit is configuredto generate, based on an open signal issued when said damper is opened,a first signal for stopping the operation of said spray device after theelapse of the first time period, and said control unit is configured tostop the operation of said spray device based on the first signal. 4.The refrigerator according to claim 1, wherein said delay unit isconfigured to generate, based on a close signal issued when said damperis closed, a second signal for starting the operation of said spraydevice after the elapse of the second time period, and said control unitis configured to start the operation of said spray device based on thesecond signal.
 5. The refrigerator according to claim 1, wherein saidstorage compartment includes: a first storage compartment which isdisposed on a way of the air passage and to which the mist is supplied,and a second storage compartment disposed upstream of said first storagecompartment; and an inside temperature detection unit configured todetect a temperature of said second storage compartment, and saidcontrol unit is configured to generate the open signal when a result ofthe detection by said inside temperature detection unit exceeds apredetermined threshold range, and to generate the close signal when theresult of the detection falls below the predetermined threshold range.6. The refrigerator according to claim 1, further comprising acondensation prevention heater configured to dry a periphery of saidspray device by heating, wherein said control unit is configured tocause said condensation prevention heater to operate for a predetermineddrying period until the close signal is received when said damper is ina closed state and said spray device is in operation based on the closesignal and the second signal.
 7. The refrigerator according to claim 6,wherein said control unit is configured to cause said condensationprevention heater to operate in one of a plurality of occurrences of asituation in which said damper is in a closed state and said spraydevice is in operation.
 8. The refrigerator according to claim 1,wherein said spray device includes: a thin rod-shaped atomizingelectrode; a counter electrode which is disposed so as to oppose and bespatially apart from said atomizing electrode; and a voltage applyingunit configured to apply a voltage across said atomizing electrode andsaid counter electrode with said atomizing electrode at a negativepotential and said counter electrode at a reference potential.
 9. Amethod of refrigeration comprising: spraying mist into a first storagecompartment by a spray device which utilizes an electrostaticatomization system, the first storage compartment being disposed on away of an air passage which is a passage for forcibly circulating coldair which is a gas that has been cooled in a cooling compartment;opening the air passage upstream of the first storage compartment by adamper; and stopping an operation of the spray device after an elapse ofa first time period since the damper is opened.
 10. A method ofrefrigeration comprising: spraying mist into a first storage compartmentby a spray device which utilizes an electrostatic atomization system,the first storage compartment being disposed on a way of an air passagewhich is a passage for forcibly circulating cold air which is a gas thathas been cooled in a cooling compartment; closing the air passageupstream of the first storage compartment by a damper; and starting anoperation of said spray device after an elapse of a second time periodsince the damper is closed.
 11. The method of refrigeration according toclaim 9, further comprising charging the mist negatively.
 12. Therefrigerator according to claim 2, wherein said storage compartmentincludes: a first storage compartment which is disposed on a way of theair passage and to which the mist is supplied, and a second storagecompartment disposed upstream of said first storage compartment; and aninside temperature detection unit configured to detect a temperature ofsaid second storage compartment, and said control unit is configured togenerate the open signal when a result of the detection by said insidetemperature detection unit exceeds a predetermined threshold range, andto generate the close signal when the result of the detection fallsbelow the predetermined threshold range.
 13. The refrigerator accordingto claim 3, wherein said storage compartment includes: a first storagecompartment which is disposed on a way of the air passage and to whichthe mist is supplied, and a second storage compartment disposed upstreamof said first storage compartment; and an inside temperature detectionunit configured to detect a temperature of said second storagecompartment, and said control unit is configured to generate the opensignal when a result of the detection by said inside temperaturedetection unit exceeds a predetermined threshold range, and to generatethe close signal when the result of the detection falls below thepredetermined threshold range.
 14. The refrigerator according to claim4, wherein said storage compartment includes: a first storagecompartment which is disposed on a way of the air passage and to whichthe mist is supplied, and a second storage compartment disposed upstreamof said first storage compartment; and an inside temperature detectionunit configured to detect a temperature of said second storagecompartment, and said control unit is configured to generate the opensignal when a result of the detection by said inside temperaturedetection unit exceeds a predetermined threshold range, and to generatethe close signal when the result of the detection falls below thepredetermined threshold range.
 15. The method of refrigeration accordingto claim 10, further comprising charging the mist negatively.